The Presence of Colony-Stimulating Factor-1 and Its Receptor in Different Cells of the Testis; It Involved in the Development of Spermatogenesis In Vitro

Spermatogenesis is a complex process, in which spermatogonial cells proliferate and differentiate in the seminiferous tubules of the testis to generate sperm. This process is under the regulation of endocrine and testicular paracrine/autocrine factors. In the present study, we demonstrated that colony stimulating factor-1 (CSF-1) is produced by mouse testicular macrophages, Leydig, Sertoli, peritubular cells and spermatogonial cells (such as CDH1-positively stained cells; a marker of spermatogonial cells). In addition, we demonstrated the presence of CSF-1 and its receptor (CSF-1R) in testicular macrophages, Leydig, Sertoli, peritubular cells and spermatogonial cells of human testis. We also show that the protein levels of CSF-1 were the highest in testis of 1-week-old mice and significantly decreased with age (2–12-week-old). However, the transcriptome levels of CSF-1 significantly increased in 2–3-week-old compared to 1-week-old, and thereafter significantly decreased with age. On the other hand, the transcriptome levels of CSF-1R was significantly higher in mouse testicular tissue of all examined ages (2–12-week-old) compared to 1-week-old. Our results demonstrate the involvement of CSF-1 in the induction the proliferation and differentiation of spermatogonial cells to meiotic and postmeiotic stages (BOULE- and ACROSIN-positive cells) under in vitro culture conditions, using methylcellulose culture system (MCS). Thus, it is possible to suggest that CSF-1 system, as a testicular paracrine/autocrine system, is involved in the development of different stages of spermatogenesis and may be used in the development of future therapeutic strategies for treatment of male infertility.

Interleukin-34, a Novel Paracrine/Autocrine Factor in Mouse Testis, and Its Possible Role in the Development of Spermatogonial Cells In Vitro

Spermatogenesis is the process of spermatogonial stem cell (SSC) proliferation and differentiation to generate sperm. This process is regulated by cell–cell interactions between Sertoli cells and developing SSCs by autocrine/paracrine and endocrine factors. It is also affected by cells in the interstitial compartment, such as Leydig cells and peritubular cells. Here, we demonstrate, for the first time, the presence of interleukin-34 (IL-34) in Leydig, Sertoli, and peritubular cells and in the premeiotic, meiotic, and postmeiotic cells. Its receptor, colony-stimulating factor-1 (CSF-1), has already been demonstrated in Leydig, Sertoli, premeiotic, and meiotic cells. IL-34 was detected in testicular homogenates and Sertoli cell-conditioned media, and was affected by mouse age. We showed that the addition of IL-34 in vitro to isolated cells from the seminiferous tubules of 7-day-old mice, using the methylcellulose culture system (MCS), increased the percentages and expression of the premeiotic cells (VASA), the meiotic cells (BOULE), and the meiotic/postmeiotic cells (ACROSIN) after four weeks of culture, when examined by immunofluorescence staining (IF) and qPCR analysis. It is possible to suggest that IL-34 is a novel paracrine/autocrine factor involved in the development of spermatogenesis. This factor may be used in future therapeutic strategies for the treatment of male infertility.

Approaches and Technologies in Male Fertility Preservation

Male fertility preservation is required when treatment with an aggressive chemo-/-radiotherapy, which may lead to irreversible sterility. Due to new and efficient protocols of cancer treatments, surviving rates are more than 80%. Thus, these patients are looking forward to family life and fathering their own biological children after treatments. Whereas adult men can cryopreserve their sperm for future use in assistance reproductive technologies (ART), this is not an option in prepubertal boys who cannot produce sperm at this age. In this review, we summarize the different technologies for male fertility preservation with emphasize on prepubertal, which have already been examined and/or demonstrated in vivo and/or in vitro using animal models and, in some cases, using human tissues. We discuss the limitation of these technologies for use in human fertility preservation. This update review can assist physicians and patients who are scheduled for aggressive chemo-/radiotherapy, specifically prepubertal males and their parents who need to know about the risks of the treatment on their future fertility and the possible present option of fertility preservation.

Identification of Premeiotic, Meiotic, and Postmeiotic Cells in Testicular Biopsies Without Sperm from Sertoli Cell-Only Syndrome Patients

Sertoli cell-only syndrome (SCOS) affects about 26.3⁻57.8% of azoospermic men, with their seminiferous tubules containing only Sertoli cells. Recently, it was reported that testicular biopsies from nonobstructive azoospermic (NOA) patients contained germ cells, and that sperm could be found in the tubules of 20% of SCOS patients using testicular sperm extraction technology. Since the patients without sperm in their testicular biopsies do not have therapy to help them to father a biological child, in vitro maturation of spermatogonial stem cells (SSCs) isolated from their testis is a new approach for possible future infertility treatment. Recently, the induction of human and mice SSCs proliferation and differentiation was demonstrated using different culture systems. Our group reported the induction of spermatogonial cell proliferation and differentiation to meiotic and postmeiotic stages in mice, rhesus monkeys, and prepubertal boys with cancer using 3D agar and methylcellulose (MCS) culture systems. The aim of the study was to identify the type of spermatogenic cells present in biopsies without sperm from SCOS patients, and to examine the possibility of inducing spermatogenesis from isolated spermatogonial cells of these biopsies in vitro using 3D MCS. We used nine biopsies without sperm from SCOS patients, and the presence of spermatogenic markers was evaluated by PCR and specific immunofluorescence staining analyses. Isolated testicular cells were cultured in MCS in the presence of StemPro enriched media with different growth factors and the development of colonies/clusters was examined microscopically. We examined the presence of cells from the different stages of spermatogenesis before and after culture in MCS for 3⁻7 weeks. Our results indicated that these biopsies showed the presence of premeiotic markers (two to seven markers/biopsy), meiotic markers (of nine biopsies, cAMP responsive element modulator-1 (CREM-1) was detected in five, lactate dehydrogenase (LDH) in five, and BOULE in three) and postmeiotic markers (protamine was detected in six biopsies and acrosin in three). In addition, we were able to induce the development of meiotic and/or postmeiotic stages from spermatogonial cells isolated from three biopsies. Thus, our study shows for the first time the presence of meiotic and/or postmeiotic cells in biopsies without the sperm of SCOS patients. Isolated cells from some of these biopsies could be induced to meiotic and/or postmeiotic stages under in vitro culture conditions.